Non-cellular Life

Non-cellular life is life that exists without a cellular structure. This term presumes the phylogenetic scientific classification of viruses as lifeforms, which is a controversial issue.

Hypothesized artificial life, self-replicating machines, and most simple molecules capable of self-replication, such as crystals, are not usually considered living. (See definition of life.)

Some biologists refer to wholly syncytial organisms as "acellular" because their bodies contain multiple nuclei which are not separated by cell membranes, however these cell-bound organisms are outside the scope of the present article.